Mark D. Neuman, MD, from the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, and colleagues conducted a textual analysis of 11 class I ACC/AHA guidelines published between 1998–2007 and revised from 2006–2013. Variations in the durability were characterized.

The researchers found that 80.0% of the 619 index recommendations were retained in the subsequent guideline version; 9.2% were downgraded or reversed; and 10.8% were omitted. Across guidelines, there was variation in the percentage of recommendations retained, from 15.4 to 94.1%. The percentage of recommendations with available information on level of evidence that were retained was 90.5% for recommendations supported by multiple randomized studies, compared with 81.0% for those supported by one randomized trial or observational data and 73.7% for those supported by opinion. Recommendations based on opinion or on one trial or observational data had a significantly higher probability of being downgraded, reversed, or omitted, compared with those based on multiple trials (odds ratios, 3.14 and 3.49, respectively).

"The durability of class I cardiology guideline recommendations for procedures and treatments promulgated by the ACC/AHA varied across individual guidelines and levels of evidence," the authors write.

One author disclosed financial ties to the pharmaceutical and health insurance industries.